Отправлено 06.08.2005 - 11:46:51
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Due to a lack of any reasonably clear written guide that I can find,
I have formed my own opinion about the grading of modern proof coins.
As this is my own opinion, it may deviate substantially from what the
grading services are looking for. Also, this is really a guide for 1936
and later proofs.
Any and all comments, corrections, etc are very welcome. Please email mevia the address given on my home page (use your browsers "back" button).
First some rationalization:
Proofs are individually multiply struck with polished dies on polished
planchets and handled individually. Proofs should not have any contact
marks on them. Proofs should have mirrored fields. Proofs should be
fully struck. Because these are the expected qualities of a proof, these
attributes set a baseline so that the grade is lowered harshly if the
proof does not live up to the standard. Most proofs should grade PR65,
except those made since 1986 or so where PR67 is more typical.
Marks on proofs:
I have identified 4 common sources of marks on proof coins:
Contact marks (post strike injury to the coin)
Metal particle strike through (tiny divots on the coin)
Lint strike through (usually a tiny bit of string)
Planchet roughness (struck over defects on the planchet)
Since a proof is supposed to be individually handled, I automatically
drop the grade to PR64 if there are *any* contact marks visible under 2X
magnification. If a proof has marks equivalent to MS64, it is PR60.
Strike throughs are very common and must be evaluated based on position.
I tiny spot next to the rim, or hidden in hair costs no more than 0.25
grade point per spot. A struck through piece of lint that makes Susan B
Anthony look like she has a booger hanging from her nose may be humorous but it is an aesthetic disaster, and would drop the grade to PR64 or lower.
Generally strike throughs in the field in front of the effigy face are
the worst detractors, with strike throughs on the effigy face running a
Planchet roughness varies considerably in character depending on how well struck the coin is and if the roughness is in the field or devices.
Planchet roughness on the high points of a not quite fully struck proof
may be confused with contact marks, and cost nearly as deaply. I will
not grade any piece with the characteristic bright patch and mushed over
line or two above PR65 (the piece must be essentially perfect in every
other respect to acheive that grade). See also strike quality. On large
coins, particularly Ikes, the planchets were so rough that roughness is
visible in the field (the most well struck part of the coin). The
roughness is visible as an unevenness in the field and is usually best
seen under a point light with the coin viewed at an acute angle. On an
otherwise perfect coin, if any of this muted planchet roughness is
visible I limit the grade to PR67 (lower if the roughness is obvious).
See also planchet roughness. A proof is supposed to be fully struck.
The coins are multiply struck so that this is more likely. Still,
striking problems frequently occur on certain issues. If the strike is
so weak that part of the design is simply not raised, then I limit the
grade to PR63. More often the striking weakness is visible on frosty
coins as a bright patch on the high points. I limit the grade of any
coin with this problem to PR65. Don't forget to check the lettering and
Field mirrors and cameo:
These are actually separate but related issues. Field mirrors is a
rating of how perfect polished the fields appear. When viewed straight
on perfect mirror fields should look black. Die erosion lines often
cause the coin to reflect a bit of light, and these are not a good
feature on a proof. Die erosion lines can be viewed with a strong (6x or
more) magnifier with the coins tilted to an acute angle under a point
light source. I limit coins with more than one or two die erosion lines
per side to PR67, coins that reflect noticeable light to PR65, and coins
that look like nice UNCs (usually dimes) to PR63.
Cameo is a rating of the amount of "frost" on the effigy and lettering
that is present on the coin. A coin is cameo if the fields are nearly
black and the devices are covered with a uniform or nearly uniform light
"white" frost. A coin is ultra-cameo if the fields are pitch black and
the devices are uniformly caked over with white frost. I will not grade
a proof PR68 or higher unless it is ultra cameo.
This is much more difficult to judge on proofs than on business strike
coins because the mint so frequently repolishes the dies, hidding the die
erosion. However, certain details have a tendency to erode away: the
bell lines on Franklin halves, the steps on Jefferson nickels, and the
lines on the columns on memorial cents. Matters are worse for the
1977-1988 period during which the mint artificially frosted the dies
repeatedly, resulting in "mushy" proof coins. This is mostly a judgement
call, and requires a good deal of familiarity with what the coins are
supposed to look like. I deduct anywhere from 1 to 5 points for mushyness.
Coins tone, it is quite difficult to completely stop. Some toning can be
very attractive, particularly if it is translucent, irridescent, and
uniform or rainbow. However, splotchy or opaque toning detracts seriously from the eye appeal of the coin. I will not grade a coin with opaque toning above PR64; PR63 if the fields are mostly dull looking from the toning. This is because you cannot see the bright mirror proof fields on the coin if the toning is opaque. I will not grade a coin with splotchy
toning above PR65. I may add a point for very pretty toning, particularly
for uniform golden toning on copper-nickel coins (Alan Herbert says this
is not toning at all, but that a very thin coating of copper sometimes gets
transfered in the planchet annealing process), or rainbow toning (usually
anular from storage in an album, but sometimes starting from the center
Zinc cents pose special problems. Very often the planchets bubble.
Since I feel that once such bubbles have started they will only get worse
with time, I will not grade a piece with such bubbles above PR60.
Sometimes the dies cut all of the way through the copper coating. This
is most frequently seen on the tops of "IN GOD WE TRUST" as tiny bright
silver spots. I'm not quite sure what affect this should have on the
grade, if any.
Pre 1965 coins with ultra cameo appearance are rare. Common dates
are typically priced in the $100+ range for the larger denominations. A
peculiar roughness in the fields (multitudes of little pointed pips) is
common on these coins, particularly the cents; this is not a good feature
and I do not grade such coins above PR65.
SMS coins with ultra cameo or cameo appearance are very rare and command large premium values. 6 step cameo SMS nickels are prohibitively rare and expensive.
1968-1976 coins mostly come with weak cameo or no cameo. 1969-S half
dollars are the only exception that I know of, as maybe 25% of these
coins are cameo. Ultra cameo coins in this date range are scarce
and command a good premium.
From 1977 to 1988 the mint either etched or sandblasted the dies
periodically in order to maintain device frost. A coin in this date range
with less than a cameo appearance is not really acceptable. Ultra cameo
on most years is still elusive and worth a modest premium. For who knows what reason, 1986 and 1987 coins are very common ultracameo (over 50% of all halves are ultracameo, don't pay a premium for this). Early 1980s halves frequently have striking weakness on and in front of Kennedy's ear.The halves in the Prestige sets seem to come better than the halves in the regular sets. Suzy bucks frequently have striking weakness behind the eye and on the cheek bone.
From 1989 on, the mint started a new process to artificially frost the
dies. The appearance of this frost is quite different than on any
previous year, as the devices have a strong cartwheel luster effect.
Cameo and near ultra cameo coins are the rule. True ultra cameo coins
are worth a small premium, but note that the new processing precludes any "caked on frost", this rating primarily comes on coins with black fields.
Dimes of all years have the worst mirrors of any denomination. Ultra
cameo dimes should, but don't command more generous premiums than the others.
Jefferson nickels frequently show planchet roughness on the lower rear
edge of the jaw, and an incomplete bottom step to Monticello (often
merging with the 5th step at the far right).
Happy cherry picking: a sharp eye and deligence can turn up wonderful
modern proofs at bargain basement prices.